A task without a deadline is just wishful thinking.

Sometimes, you can get away with procrastinating. If you never get around to alphabetizing your spices, no one’s life will change. But putting off some tasks could have a huge impact on loved ones.

The close of the year is a good time to set some firm deadlines to make sure you won’t leave a financial mess for people you love if you unexpectedly die or become incapacitated. Consider putting these items on your to-do list with a Dec. 31 due date:

1. CHECK YOUR BENEFICIARIES

If you need convincing that updating beneficiaries is important, consi...